Neuromuscular Conditions Research Articles

Neurologic Disease Is a Risk Factor for Revision After Lumbar Spine Fusion.

Study Design:Medicare database analysis.Objective:The purpose of this study was to investigate whether neurologic disorders represent a risk factor for revision after lumbar spine surgery.Methods:Patients who underwent lumbar spine surgery were identified from 5% Medicare Part B claims between 2005 and 2008. Cox regression analysis was used to evaluate risk factors for revision within the 7 years after the index lumbar surgery. Covariates included age, gender, race, census region, Medicare buy-in status, Charlson score, year, prior lumbar fusion within 2 years of index surgery, prior diagnosis of cervical spondylotic myelopathy treated with or without cervical spine surgery, and diagnoses of other neuromuscular conditions.Results:Of 8665 cases who had decompression only, 401 (5%) had a revision within 7 years after the index surgery. Factors predictive of revision were prior lumbar fusion (hazard ratio [HR] = 2.78, confidence interval [CI] = 1.43-5.37, P = .002) and being female (HR = 1.61, CI = 1.31-1.97, P < .001). Of 5501 cases who had a decompression and fusion, 752 (14%) had a revision surgery within 7 years after the index surgery. Factors predictive of revision were the presence of a neurologic disorder (HR = 1.24, CI = 1.05-1.46, P = .010), prior lumbar fusion (HR = 3.09, CI = 2.05-4.63, P < .001), and being female (HR = 1.35, CI = 1.15-1.57, P < .001).Conclusions:An increase in revision rate (P = 0.01, HR = 1.24) was seen in patients with neurologic disorders undergoing lumbar decompression and fusion, although not for patients undergoing decompression alone. This suggests an opportunity to improve clinical outcome and reduce revision rate through improved surgical decision making or treatment of the neurologic disorder.

Targeted therapies for congenital myasthenic syndromes: systematic review and steps towards a treatabolome.

Despite recent scientific advances, most rare genetic diseases — including most neuromuscular diseases — do not currently have curative gene-based therapies available. However, in some cases, such as vitamin, cofactor or enzyme deficiencies, channelopathies and disorders of the neuromuscular junction, a confirmed genetic diagnosis provides guidance on treatment, with drugs available that may significantly alter the disease course, improve functional ability and extend life expectancy. Nevertheless, many treatable patients remain undiagnosed or do not receive treatment even after genetic diagnosis. The growth of computer-aided genetic analysis systems that enable clinicians to diagnose their undiagnosed patients has not yet been matched by genetics-based decision-support systems for treatment guidance. Generating a ‘treatabolome’ of treatable variants and the evidence for the treatment has the potential to increase treatment rates for treatable conditions. Here, we use the congenital myasthenic syndromes (CMS), a group of clinically and genetically heterogeneous but frequently treatable neuromuscular conditions, to illustrate the steps in the creation of a treatabolome for rare inherited diseases. We perform a systematic review of the evidence for pharmacological treatment of each CMS type, gathering evidence from 207 studies of over 1000 patients and stratifying by genetic defect, as treatment varies depending on the underlying cause. We assess the strength and quality of the evidence and create a dataset that provides the foundation for a computer-aided system to enable clinicians to gain easier access to information about treatable variants and the evidence they need to consider.

Texture analysis of sonographic muscle images can distinguish myopathic conditions.

Given the recent technological advent of muscle ultrasound (US), classification of various myopathic conditions could be possible, especially by mathematical analysis of muscular fine structure called texture analysis. We prospectively enrolled patients with three neuromuscular conditions and their lower leg US images were quantitatively analyzed by texture analysis and machine learning methodology in the following subjects : Inclusion body myositis (IBM) [N=11] ; myotonic dystrophy type 1 (DM1) [N=19] ; polymyositis/dermatomyositis (PM-DM) [N=21]. Although three-group analysis achieved up to 58.8% accuracy, two-group analysis of IBM plus PM-DM versus DM1 showed 78.4% accuracy. Despite the small number of subjects, texture analysis of muscle US followed by machine learning might be expected to be useful in identifying myopathic conditions. J. Med. Invest. 66 : 237-240, August, 2019.

CE: Managing Movement Disorders: A Clinical Review.

: Neuromuscular disorders are complex, difficult both to differentiate and to manage. Yet nurses, who encounter a symptomatically diverse neuromuscular patient population in various practice settings, are expected to be well versed in managing the variable associated symptoms of these disorders. Here the authors discuss how to assess such neuromuscular conditions as muscle tightness, spasticity, and clonus; the pathophysiology underlying each; and the available recommended treatments, an understanding of which is necessary for successful symptom management and clear provider-patient communication.

Hipotonia e dificuldades alimentares no recém-nascido: um caso de distrofia miotónica tipo 1 congénita

Introduction: Congenital myotonic dystrophy type 1 (DM1) is characterized by hypotonia and severe general weakness at birth, often with respiratory distress and even death. Clinical report:A newborn male with prenatal diagnosis of ventriculomegaly and polyhydramnios was born at 39 weeks of gestation with no immediate occurrences and a maternal family history of two cases with unspecified neuromuscular conditions. The newborn was admitted in the second day of life due to feeding problems and desaturation episodes, presenting with hypotonia, non-vigorous crying, facial diplegia, and arthrogryposis of the lower limbs. A genetic study for myotonic dystrophy was requested, which revealed cytosine thiamine and guanine (CTG) expansion in the DMPK gene (1100−1400 repeats), confirming diagnosis of congenital DM1. Discussion and conclusions: Despite the presence of congenital DM1, this newborn presents with a milder phenotype than expected for the condition. Symptom recognition, combined with family history, allowed an early diagnosis and adequate follow-up.

National survey: current prevalence and characteristics of home mechanical ventilation in Hungary

BackgroundHome mechanical ventilation is an established treatment for chronic respiratory failure resulting in improved survival and quality of life. Technological advancement, evolving health care reimbursement systems and newly implemented national guidelines result in increased utilization worldwide. Prevalence shows great geographical variations and data on East-Central European practice has been scarce to date. The aim of the current study was to evaluate prevalence and characteristics of home mechanical ventilation in Hungary.MethodsWe conducted a nationwide study using an online survey focusing on patients receiving ventilatory support at home. The survey focused on characterization of the site (affiliation, type), experience with home mechanical ventilation, number of patients treated, indication for home mechanical ventilation (disease type), description of home mechanical ventilation (invasive/noninvasive, ventilation hours, duration of ventilation) and description of the care provided (type of follow up visits, hospitalization need, reimbursement).ResultsOur survey uncovered a total of 384 patients amounting to a prevalence of 3.9/100,000 in Hungary. 10.4% of patients received invasive, while 89.6% received noninvasive ventilation. The most frequent diagnosis was central hypopnea syndromes (60%), while pulmonary (20%), neuromuscular (11%) and chest wall disorders (7%) were less frequent indications. Daily ventilation need was less than 8 h in 74.2%, between 8 and 16 h in 15.4% and more than 16 h in 10.4% of patients reported. When comparing sites with a limited (< 50 patients) versus substantial (> 50 patients) case number, we found the former had significantly higher ratio of neuromuscular conditions, were more likely to ventilate invasively, with more than 16 h/day ventilation need and were more likely to provide home visits and readmit patients (p < 0,001).ConclusionsOur results show a reasonable current estimate and characterization of home mechanical ventilation practice in Hungary. Although a growing practice can be assumed, current prevalence is still markedly reduced compared to international data reported, the duality of current data hinting to a possible gap in diagnosis and care for more dependent patients. This points to the importance of establishing home mechanical ventilation centers, where increased experience will enable state of the art care to more dependent patients as well, increasing overall prevalence.

Current Cardiac Imaging Approaches in Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular condition caused by mutations in the dystrophin gene leading to skeletal muscle weakness and dilated cardiomyopathy. The prevalence of DMD-related cardiomyopathy increases with age and is almost universal by the third decade of life. Myocardial fibrosis and progressive left ventricular dysfunction lead to the development of heart failure and premature death. With modern advances in medical and surgical management for patients with DMD increasing their life expectancy, cardiac dysfunction represents an increasing cause of morbidity and mortality in these patients. Early diagnosis of dilated cardiomyopathy before symptom development enables the initiation of potentially disease-modifying therapies, but requires regular dedicated imaging surveillance with sufficient sensitivity to detect subclinical changes in cardiac structure and function. Currently, transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMR) are commonly used and have complementary roles. TTE is rapid and readily available, whereas CMR is the gold standard for the quantification of ventricular structure and function and can detect the presence and extent of myocardial fibrosis, an increasingly appreciated marker for early disease. This review describes the clinical applications, advantages, and disadvantages of cardiac imaging screening and surveillance for the myocardial manifestations of DMD, with a particular focus on TTE and CMR.

SIL1 deficiency causes degenerative changes of peripheral nerves and neuromuscular junctions in fish, mice and human

BackgroundMarinesco-Sjögren Syndrome (MSS) is a rare neuromuscular condition caused by recessive mutations in the SIL1 gene resulting in the absence of functional SIL1 protein, a co-chaperone for the major ER chaperone, BiP. As BiP is decisive for proper protein processing, loss of SIL1 results in the accumulation of misshaped proteins. This accumulation likely damages and destroys cells in vulnerable tissues, leading to congenital cataracts, cerebellar ataxia, vacuolar myopathy and other MSS phenotypes. Whether the peripheral nervous system (PNS) is affected in MSS has not been conclusively shown. MethodsTo study PNS vulnerability in MSS, intramuscular nerves fibres from MSS patients and from SIL1-deficient mice (woozy) as well as sciatic nerves and neuromuscular junctions (NMJ) from these mice have been investigated via transmission electron microscopic and immunofluorescence studies accompanied by transcript studies and unbiased proteomic profiling. In addition, PNS and NMJ integrity were analyzed via immunofluorescence studies in an MSS-zebrafish model which has been generated for that purpose. ResultsElectron microscopy revealed morphological changes indicative of impaired autophagy and mitochondrial maintenance in distal axons and in Schwann cells. Moreover, changes of the morphology of NMJs as well as of transcripts encoding proteins important for NMJ function were detected in woozy mice. These findings were in line with a grossly abnormal structure of NMJs in SIL1-deficient zebrafish embryos. Proteome profiling of sciatic nerve specimens from woozy mice revealed altered levels of proteins implicated in neuronal maintenance suggesting the activation of compensatory mechanisms. ConclusionTaken together, our combined data expand the spectrum of tissues affected by SIL1-loss and suggest that impaired neuromuscular transmission might be part of MSS pathophysiology.

A qualitative study of experiences of health and social care in home mechanical ventilation.

AimTo contribute insight into health and social care integration through an exploration of the care experiences of adults with degenerative neuromuscular conditions who use a mechanical ventilator at home.DesignDescriptive qualitative research.MethodsSeventeen semi‐structured interviews were conducted with patients and family carers living in Scotland during 2015–2016 and thematically analysed.ResultsTo achieve a satisfying life, home ventilated participants required help from a variety of health and social care services, as well as care from family. Examples of successful care were identified, but there were also serious failures and conflict with services. Identifying how care fails or succeeds for this patient population and their families requires an understanding of the interdependency of health and social care. This was achieved by examining health and social care provision from the experiential perspective of care‐users to provide insights into how disconnected provision has an impact on users’ lives in numerous, idiosyncratic ways.

USE OF SPIROMETRY FOR DIAGNOSIS AND MANAGEMENT OF ASTHMA IN A COMMUNITY HEALTH CENTER

Introduction Guidelines recommend spirometry for diagnosing and managing asthma, but previous reports suggest that spirometry is underused, especially in patients who are nonwhite, lower income, or cared for by primary care (rather than subspecialist) physicians. Methods We conducted a restrospective cohort study that identified patients in 2014 and examined records up to 7 years prior. We included patients 18 years or older who had had a visit during 2014 where they received a diagnosis code for asthma. We excluded patients with neuromuscular conditions or history of pneumonectomy. We determined use of spirometry at the time of diagnosis and subsequently. Results We identified 394 patients; of these, 28% were men; 11% were African American and 39% identified as Latino. The majority (55%) were covered by either Medicaid or Medicare. Almost all (99%) patients received a medication for asthma during the study period. Of the 394, 208 patients (52.8 percent) received spirometry at any point; 140 (67%) of these were conducted at the time of diagnosis; 61 (29%) had a methacholine challenge at any time. Only 85 of the 208 patients who had an initial study done (and 21% of the 394) had follow-up spirometry documented. Conclusions Although guidelines recommend initial and recurrent spirometry to monitor pulmonary function in patients with asthma, only about half of patients received spirometry at the time of diagnosis and only 21% of patients received follow-up spirometry. Future interventions should focus on identifying barriers to use of spirometry for primary care physicians who treat asthma in high-risk populations.

Incidence of pediatric venous thromboembolism after elective spine and lower extremity surgery in children with neuromuscular complex chronic conditions: do we need prophylaxis?

Incidence of pediatric venous thromboembolism after elective spine and lower extremity surgery in children with neuromuscular complex chronic conditions: do we need prophylaxis?

Fecal microbiota profile in a group of myasthenia gravis patients

The intestinal microbiota plays a key role in the maintenance of human health. Alterations in this microbiota have been described in several autoimmune diseases, including nervous system diseases. Nevertheless, the information regarding neuromuscular conditions is still limited. In this study, we aimed at characterizing the intestinal microbiota composition in myasthenia gravis patients (MG). To this end fecal samples were taken from ten patients, with antibodies against the acetylcholine receptor, and ten age and sex matched controls from the same population (Asturias region, Spain). Fecal samples were submitted to microbiota analyses by 16S rRNA gene profiling, bifidobacterial ITS-region profiling and qPCR. The fecal levels of short chain fatty acids were determined by gas chromatography. MG patients were found to harbor lower relative proportions of Verrucomicrobiaceae and Bifidobacteriaceae, among others, and increased of the phylum Bacteroidetes and the family Desulfovibrionaceae. The increase of these latter microbial groups was also confirmed at quantitative level by qPCR. In contrast, no statistically significant differences were found between MG patients and the control group in the bifidobacterial population at the species level or in short chain fatty acids profiles. Our data indicates an altered fecal microbiota pattern in MG patients and point out at specific microbiota targets for intervention in this population.

Multidisciplinary Perioperative Care for Children with Neuromuscular Disorders.

Children with neuromuscular diseases present unique challenges to providing safe and appropriate perioperative care. Given the spectrum of disease etiologies and manifestations, this is a population that often requires specialized multidisciplinary care from pediatricians, geneticists, neurologists, dieticians, and pulmonologists which must also be coordinated with surgeons and anesthesiologists when these patients present for surgery. Several of these diseases also have specific pharmacologic implications for anesthesia, most notably mitochondrial disease and muscular dystrophies, which put them at additional risk during the perioperative period particularly in patients presenting without a formal diagnosis. Techniques and strategies to fully evaluate and optimize these patients preoperatively, manage them safely intraoperatively, and return them to their baseline status postoperative are particularly important in this vulnerable group of patients. Utilizing a review of inherited neuromuscular conditions, generalized perioperative concerns, and specific complications related to anesthesia, this article provides an overview of pertinent considerations and recommends a framework for management of these patients.

REGISTRIES AND CARE OF NEUROMUSCULAR DISORDERS: P.278How can we ensure children with neuromuscular conditions achieve personally meaningful futures?

REGISTRIES AND CARE OF NEUROMUSCULAR DISORDERS: P.278How can we ensure children with neuromuscular conditions achieve personally meaningful futures?

PMU51 - The Identification of Patient-Centric Value Drivers for Self-Paid Treatments in Asia

To assess patients' aspirations during their treatment journey in Asia, which will support the identification of value drivers that resonate with patients and drive their choice of treatment and willingness to pay A high level meta-analysis was conducted across relevant studies (n=6) undertaken by GfK since July 2016 involving the assessment of patient journeys of those affected by oncology, immunology and neuromuscular conditions in Singapore, Taiwan, China, Hong Kong and Japan. Primary focus was to assess drivers for treatment initiation and continuation. The studies involved secondary and primary research on patients’ aspirations from the perspective of patients, physicians, nurses and caregivers. MaxDiff analysis was employed to confirm the ranking of value drivers. The analysis identified many commonalities in patient aspirations across the different therapeutic areas. Compared to patients that are taking reimbursed therapies, those who are paying out-of-pocket costs for medications are more involved in treatment decision making. For those who suffer from oncology and neuromuscular conditions, prolonging life is not as attractive if they cannot have good quality of life (QoL). Immunology patients see similar importance in QoL and consider being able to resume their daily routine the greatest driver for treatment choice. There are also subtle value driver differences between treatment initiation and continuation – cost can be a key barrier for initiation but it rarely causes discontinuation whereas safety/ tolerability issues are the opposite. Moreover, caregivers have better understanding of patient value drivers compared to physicians or nurses. Shared decision making in medicine has become more common in Asia and clear communication on QoL benefits are important to drive patient-focused treatment decisions and willingness to pay for self-pay treatment. However, there is evidence of an understanding gap, and a consequent need to improve patient-physician communication.

SYNE1-related autosomal recessive cerebellar ataxia, congenital cerebellar hypoplasia, and cognitive impairment.

The spectrin repeat-containing nuclear envelope protein 1 (SYNE1) gene encodes a family of spectrin structural proteins that are associated with anchoring the plasma membrane to the actin cytoskeleton. SYNE1-related disease is most commonly reported in autosomal recessive spinocerebellar ataxia 8, which demonstrates variable age of onset with a median of 30 years of age. However pathogenic mutations in SYNE1 are also causative of arthrogryposis multiplex congenital, a severe congenital neuromuscular condition. Here in we report monozygous twins with childhood onset ataxia, cerebellar hypoplasia, dysarthria, and cognitive impairment sharing two novel heterozygous mutations in the SYNE1 gene. Our family may expand the clinical phenotype associated with SYNE1-related disease and offers possible genotype-phenotype correlations of a rare continuum of clinical disease phenotypes from neonatal to adult onset.

Predictors of Obtaining Polysomnography Among Otolaryngologists Prior to Adenotonsillectomy for Childhood Sleep-Disordered Breathing.

(1) To assess the predictors for obtaining polysomnography (PSG) in children undergoing adenotonsillectomy (AT) for sleep-disordered breathing, and (2) to estimate the adherence to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guideline recommendations for pre-AT PSG. This was a retrospective cohort study of children who were seen in the Pediatric Otolaryngology Clinic and underwent AT for sleep-disordered breathing over a 13-month period at a single tertiary care children's hospital. Patients with and without pre-AT PSG were compared using bivariate and logistic regression analysis to identify predictors for PSG. Electronic medical records were reviewed for demographic variables, medical comorbidities, and PSG data. Adherence to AAO-HNS guideline recommendations was estimated by calculating the proportion of patients who had a PSG among those who met the recommended criteria for pre-AT PSG. Mean age was 6.6 ± 3.6 years with 53% male. A total of 65 of 324 children (20%) underwent PSG prior to AT. The only factor significantly associated with pre-AT PSG was age 1 to 3 years (odds ratio 4.5, 95% confidence interval [2.2, 9.0], P < .001). Among patients who met AAO-HNS criteria for pre-AT PSG, 28 of 128 (20%) underwent PSG compared to 35 of 186 (19%) who did not meet criteria (odds ratio 1.0, 95% confidence interval [0.6, 1.9], P = .87). Among children who underwent AT, the only significant predictor of obtaining pre-AT PSG was age 1 to 3 years. The rate of adherence to the AAO-HNS guideline recommendations was low (20%), which represents an educational opportunity.

Wednesday, September 26, 2018 10:35 AM – 12:00 PM Cervical Spine Trauma: 20. Traumatic cervical spinal cord injuries with fracture: an investigation of early versus delayed surgery among 6,636 propensity-matched patients

BACKGROUND CONTEXT Currently, optimal timing of surgical intervention for traumatic cervical spinal cord injuries (SCIs), a life-altering event and enormous economic burden, is unclear. PURPOSE Our goal was to investigate the perioperative and postoperative outcomes in patients with traumatic SCIs. STUDY DESIGN/SETTING Retrospective review. PATIENT SAMPLE A total of 28,414 SCI patients. OUTCOME MEASURES Perioperative complications, mortality, length of stay, total hospital charges, discharge disposition. METHODS HCUP's NIS was queried for ICD-9 codes pertaining to cervical SCI w/ fracture (806-806.19). Patients without traumatic etiology, neuromuscular conditions (eg, Down syndrome), with SCIWORA, and without complete time to procedure (TTP) data were excluded. Patients were stratified into 7 groups by TTP: same-day as admission (SD), 1-day delay (1D), 2-day delay (2D), 3-day delay (3D), 4-7 days delay (4-7D), 8-14 days delay (8-14D), >14 days delay (>14D). In an attempt to reduce covariate bias, groups were propensity score matched (PSM) by age, comorbidity index (CCI), mechanism of injury (MOI) (fall, MVA, pedestrian), trauma status at admission (hypotension, shock, hemorrhage, intubation), and concurrent injuries. Surgical details, perioperative complications, length of stay, total charges, and discharge disposition was compared. Binary logistic regressions determined independent predictors of varying complications (reference: same-day). RESULTS A total of 28,414 patients were included. After PSM, 6,636 patients remained (948 per group). Overall age 49.3, gender: 25.4%F, 67.4% white, 15.1% black, 11.4% hispanic, CCI: 1.2. Most common MOIs were 38.2% MVAs, 32% falls, 19.9% pedestrian accidents, 5.7% assaults, 4.2% sports. Procedure rates were 64.2% spinal fusion (36.8% 2-3 lvls, 16.1% 4-8 lvls, 1.4% >8 lvls), 32.5% decompressions, 14.7% halo/traction. SD was associated with the highest mortality (28.8% vs. 6.1-11.6%), lowest LOS (15.14 vs. 15.24-54.2days) and total hospital charges ($172,086.93 vs. $204,931.12-$545,797.14), all p 14D-OR: 10.2[3.9-26.7]), discharging to another care facility (1D-OR: 3.0[2.1-4.3] a 8-14D-OR: 3.1[2.2-4.3]), or discharging with quadriplegia (1D-OR: 1.1[0.8-1.4] a >14D-OR: 1.5[1.2-1.9], exception 3D-OR: 0.9[0.6-1.1]). 2D and 3D were significantly less likely to develop ARDS (OR: 0.8[0.6-1.0], OR: 0.9[0.7-1.1]) and any complication (OR: 0.9[0.8-1.1], OR: 0.7[0.6-0.9]), while all delay groups were less likely to develop sepsis (ORs: 0.6-0.9, exception >14D OR: 2.3[1.7-3.1]) and paraplegia (ORs 0.0-0.8) compared to SD. CONCLUSIONS Patients operated on the same day as admission were significantly less likely to develop infection, respiratory complications, or discharge to another care facility. Same-day operative patients were also less likely to discharge with quadriplegia, and more likely to discharge with paraplegia, indicating early intervention may significantly benefit discharge neurologic status. 2-day and 3-day operative patients exhibited significantly less risk of developing ARDS, and complication, or sepsis. While immediate and 2-3 day delayed operations appear to have unique advantages, patients who underwent procedures >14 days after admission were associated with poor outcomes and discharge disposition. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Children Enrolled in Hospice Care Under Commercial Insurance: A Comparison of Different Age Groups.

Although most children at end of life have commercial insurance, little is known about their demographic and clinical characteristics, what care they are receiving, and how much it costs. To describe commercially insured children who enrolled in hospice care during their last year of life and to examine differences across age-groups. A retrospective cohort study was conducted using 2005 to 2014 data from the MarketScan Commercial Claims and Encounters database from Truven Health Analytics. Variables were created for demographics, health, utilization, and spending. Analyses included χ2 and analysis of variance tests of differences. Among the 17 062 children who utilized hospice, 49% had a preferred provider organization (PPO). Hospice length of stay averaged less than 5 days. Over 80% of children visited their primary care physician. Eight percent had hospital readmissions, and 38% had emergency department (ED) visits. Average expenditures were US$3686 per month or US$44 232 annually. The most common condition for children less than 1 year was cardiovascular (21.96%). Neuromuscular conditions were the most frequent (7.89%) in children aged 1 to 5 years, while malignancies (10.53% and 11.32%, respectively) were prevalent in ages 6 to 14 and 15 to 17. Children less than 1 year had the highest frequency of hospital readmissions (16.25%) with the lowest ED visits (28.67%) while incurring the highest expenses (US$11 211/month). The findings suggest that commercially insured children, who enroll in hospice, have flexible coverage with a PPO. Hospital readmissions and ED visits were relatively low for a population who was seriously ill. There were significant age-group differences.

P102. Upper airway obstruction induced by non-invasive ventilation using an oronasal interface

Background In a subset of patients started on nocturnal non-invasive ventilation (NIV), intermittent upper airway obstruction has been described as possibly treatment-induced. Some evidence suggests that inspiratory pressure effects and the use of an oronasal interface may promote upper airway obstruction in patients with neuromuscular disease (NMD) and amyotrophic lateral sclerosis (ALS) in particular. Methods We retrospectively evaluated clinical data from 212 patients in whom NIV was initiated using an oronasal mask. Treatment-induced upper airway obstruction was defined as an AHI > 5/h along with a relative increase of the AHI in the first treatment night compared to diagnostic sleep studies. Results Prevalence of treatment-induced upper airway obstruction was 14.2% in the entire cohort, 17.0% in patients with NMD (n = 165), 20.4% in the ALS subgroup (n = 93), and only 4.3% in patients with non-neuromuscular conditions (n = 47). In patients using a fixed expiratory positive airway pressure (EPAP) (n = 191) EPAP was significantly correlated with AHI reduction (r = 0.50; p Δ PAP) showed weak inverse correlation with the AHI change achieved in the first treatment night (r = −0.28; p Δ PAP was the only independent predictor of treatment-induced upper airway obstruction corrected for age, sex and body mass index. In patients with ALS, treatment-induced upper airway obstruction was more common than in other neuromuscular conditions and showed association with better bulbar function. Conclusions Initiation of NIV using an oronasal interface may be associated with upper airway obstruction, and a subset of patients with ALS and other NMD may be at particular risk. Careful titration of ventilator settings is recommended in these patients in order to achieve AHI normalization.